1. Field of the Invention
The present invention relates to a light emitting diode (LED), and more particularly, to a light emitting diode having an insulating substrate.
2. Description of the Prior Art
Light emitting diodes (LEDs) are employed in a wide variety of applications including optical display devices, traffic lights, data storage equipment, communication devices, illumination apparatuses, and medical treatment equipment. One of the main goals of engineers who design LEDs is to increase the brightness of the light emitted from LEDs.
U.S. Pat. No. 5,563,422 discloses a gallium nitride (GaN)-based LED in FIG. 10. The LED has a p-type ohmic contact electrode 56 made of nickel, gold or a nickel-gold alloy. The LED also has an n-type ohmic contact electrode 57 made of titanium, aluminum, or a titanium-aluminum alloy. Since the electrodes 56 and 57 are made of different materials, two evaporation processes and two photolithographic processes are required to form the electrodes 56 and 57, respectively.